The present invention relates to a method for processing of mobile originated calls in a packet switched protocol based communication network that comprises a packet switched protocol based cellular telephone network, for instance, a GSM network, and a further network, for instance, a packet switched protocol network or a general switched telephone network (GSTN) that is coupled to the cellular telephone network by means of an interface comprising a signalling information exchange function and a call or payload information exchange function between the cellular telephone network and the GSTN.
Recently, there have been made attempts in a more and more increasing manner to couple and to integrate a mobile cellular telephone network, for instance, the GSM network, that is generally a circuit switched network to a further kind of networks, called packet switched networks, for instance, an internet protocol network or VOIP (Voice on Internet Protocol) network, wherein call information is transferred in the form of xe2x80x9cpacketsxe2x80x9d between the called member and the calling member and vice versa. The packet switched network uses several different ways or through-connections in order to transfer the packets between the users, whereas in the circuit switched world, for instance, the GSM network, a through-connection is established within the network and, as long as the through-connection is maintained, the whole call information including signalling and payload information is transferred via the through-connection in the circuit switched network between the users.
A through-connection in a communication network that comprises, for instance, a GSM network or a similar cellular telephone network and an internet protocol network as GSTN being coupled with each other by interface means is established in the conventional cellular telephone network always via a base transceiver station, a base station controller and a mobile services switching centre to the interface that in turn is coupled to the internet protocol network or packet switched network. Some delay is introduced into transferring the call information, payload or signalling information on the side of the conventional cellular telephone network which renders the known architecture of the cellular telephone network improper or not very well suited for coupling to a packet switched network, for instance, an internet protocol network or similar network. In addition, the delay on the cellular telephone network side causes often a delay on the packet switched network side that lowers the overall network performance.
It is, therefore, an object of the present invention to provide a method for processing mobile originating calls in a packet switched protocol based or Internet protocol based communication network which minimises the delay problems and bandwidth requirements.
This object is solved by the method of claim 1 and by the communication network. Accordingly, the inventive method for processing a mobile originated call in a packet switched protocol based communication network comprising an packet switched protocol based cellular telephone network having a first layer for transferring signalling information assigned to the call being processed by the communication network, a second layer for transferring payload information assigned to the call, and interface means for coupling the cellular telephone network to a further network or general switched telephone network, the interface means comprising a signalling information exchange function and a payload information exchange function between the cellular telephone network and the further network, the first layer and the second layer of the cellular telephone network being coupled to the interface means, and the second layer comprising at least one base node to be coupled to at least one mobile station from which the telephone call originates, to the first layer and to the interface means, the method comprising: after initiating the processing of a call, exchanging address information identifying the base node within the cellular telephone network and identifying the interface means within the cellular telephone network between the base node and the interface means via the first layer and under control of the first layer in order to establish a through-connection within the second layer for transferring payload information of the call from the base node to the interface means and vice versa on the basis of the address information.
Since in the invention the payload of a call is routed directly within the second layer of the packet switched protocol based or IP (Internet Protocol) based cellular telephone network to or from the interface means the payload information is not transferred via the longer and more time consuming way of the conventional systems, i.e., for instance, the mobile services switching center of a conventional GSM network, and, therefore, a corresponding delay in the cellular telephone network and the delay problems involved therewith are minimised or they are avoided.
Directing the payload of the call only within the second layer, e.g. between a base station transceiver as base node and a media gateway of the interface means, is ensured since the invention establishes a network unique addressing of the base node and the interface means by using the corresponding base node address or base transceiver station address and the interface means address or media gateway address.
Further, by routing the payload information directly from the base station transceiver to the interface means, for instance, the media gateway, the bandwidth requirements for transferring the payload information are minimised.
The cellular telephone network can be, for instance, a GSM network. The further network can be or can comprise a packet switched protocol based network, for instance, the Internet, a VOIP network, an Internet Protocol network, a GPRS network or a UMTS network, or the further network can be or comprise a circuit switched network or circuit switched protocol based telephone network, for instance, a ISDN network, a PLMN network or a PSTN network.
The Communication network of the present invention comprises a packet switched protocol based cellular telephone network having a first layer for transferring signalling information assigned to a call being processed by the communication network, a second layer for transferring payload information assigned to the call, and interface means for coupling the cellular telephone network to a further network, the interface means comprises a signalling information exchange function and a payload information exchange function between the cellular telephone network and the further network, the first layer and the second layer of the cellular telephone network being coupled to the interface means, and the second layer comprising at least one base node to be coupled to at least one mobile station from which the call originates, to the first layer and to the interface means, wherein the first layer controls and transfers an exchange of address information identifying the base node within the cellular telephone network and identifying the interface means within the cellular telephone network between the base node and the interface means in order to establish a through-connection within the second layer for transferring payload information of the call from the base node to the interface means and/or vice versa on the basis of the address information.